Adjustable support for lamp sockets in light signals



J. F. MERKEL Sept. 8, 1931.

ADJUSTABLE SUPPORT FOR LAMP SOCKETS IN LIGHT SIGNALS Filed Aug. '25 1926 2 Sheets-Sheet 1 INVENTOR ATTORNEY J. F. MERKEL 1,822,105

ADJUSTABLE SUPPORT FOR LAMP SOCKETS IN LIGHT SIGNALS Sept. 8, 1931.

Filed Aug. 25, 1926 2 Sheets-Sheet 2 Fla. 6.

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Patented Elept. 8, 1931 UNlTED STATES PATENT OFFICE JOSEPH FREE] MERKEL, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMYANY, OF ROCHESTER, NEW YORK ADJUSTABLE SUPPORT FOR LAMP SQGKETS IN LIGHT SIGNALS Application filed August 25, 1926. Serial No. 131,466.

This invention relates to light signals for railway signaling purposes, and more par ticularly to devices for adjustably supporting a lamp in a light signal so that it may be moved to the position where its filament is at a predetermined point.

The typical light signal used in railway signaling ordinarily employs a lens, mirror, or like light concentrating and directing device having a definite focal point to which the light source should be located to obtain the desired range and spread. Incandescent electric lamps, commonly used as a light source in light signals, are not ordinarily manufactured so that the concentrated filament has always the same space relation to the base of the lamp, so that when different lamps are put in the same signal or in different signals, the filaments of these lamps rarely come at the right focal point. It has been proposed to support the lamp socket adjustably in the signal and provide suitable sighting or indicating means to define the point at which the filament should be located, so that when a lamp is placed in the signal, it may be shifted with the aid of the indicating means to the point where its filament comes at the right point.

In accordance with this invention, it is proposed to provide an improved form of adjustable support for the lamp socket so that it may be readily moved in three directions, preferably at right angles and along lines which have a predetermined relation to the lines of sight of the indicating means, so that the adjustment to put a lamp on focus may be performed to a better advantage.

One object of the invention is to provide an adjustable lamp support having the necessary characteristics which can be cheaply manufactured, takes up little space, can be easily manipulated with precision, in riudes adjustments which can be easily fastened to retain the particular adjustment set, and which provided for the necessary relative movement of parts in a way to maintain alignment and avoid undue friction and lost motion.

A further object of the invention is to provide a rear light for the signal, capable of giving an indication visible for a limited distance in the rear of the signal, 1n such a manner as not to detract from the elliclency of the main beam, or render the signal liable ment of finders or indicating devices to do fine the correct location of the filament; but it should be understood that this is merely a typical or illustrative application of the invention, and that the adjustable lamp support may beapplied to other types of signals and used in combination with other forms of indicating devices.

Inthe drawings, F 1 shows a rear view of light signal unit, with the rear door partly broken away to show a rear elevation of the adjustable lamp supporting means of the invention Fig. 2 shows a vertical section through the light signal unit, taken on the line 22 in Fig. 1;

Fig. 3 is a 'lt'ragmentary section through the light signal showing the back light;

Figs. a to 7 inclusive illustrate details of the construction of the adjustable lamp support; and

Fig. 8 shows a modification.

The particular type of light signal unit shown to illustrate the application of the invention comprises a casing C of a general cylindrical form with open ends and an intermediate internal peripheral flange 1. The rear of this casing is closed by a removable door 2, provided with the usual gaskets, which is held in place in any suitable way, preferably by screw studs 3, with suitable hasps, engaging lugs on the inside of the main casing. In the front end of the casing C is the outer lens 4 of the usual and well known doublet lens combination, which is held in place by a bezel ring 5 fastened by screws. The usual iood or sunshade G is convenientlv fastened by screws to an extending flange integral with this outer bezel ring 5. The inner lens 7 of the doublet combination is secured to the intermediate flange 1 of the casing by an inner bezel ring 8, fastened to said flange by scr ws 9. An opening 10 in the bottom of tae casing C, surrounded by a threaded fiange for a conduit fitting, permits wires to be convenientlv extended into the casing. it is contemplated that this unit will be secured to a suitable background, together with other units, to constitute a com plete multiple aspect signal, such as disclosed, for example, in the application of S. M. Day, Ser. No. 1211, 168 filed August 25, 1926.

In order to focus lamps of commercial manufacture in a signal, it is necessary to provide a means for defining the point atwhich the lamp filament should be located, and also means for adjusting the lamp socket. Any suitable type of finder for defining the proper location of the filament may be used in connection with the lamp usting means of this invention; and the finders F shown are merely typical and by themselves form no part of the present 'nvention, being disclosed and claimed in the appl cation of A. T. Carter, Ser. No. 181,926? filed August 25, 1926. For a clear understan ing of the functions and advantages of the adjustable lamp support of this invention, it should be understood that these finders F, fastened to the inner bezel ring 8 at points approximately 90 degrees apart, define two lines of sight intersecting in a common plane at the focal point for the doublet lens combination. Briefiy stated, each finder F comprises a mirror 12 which reflects the image of the ighted filament of the lamp through a pin hole or lens onto a ground ss in the outer end of the finder, said glass having thereon cross hairs or other point designating marks. These finders F are permanently fastened in each signal in a fixed position, preferably determined bv adjustment during the process of assemblv, so that when the images of 'lighted filament fall upon the two ground glasses of these finders at the points marked by the cross hairs, sa l d filament is on focus.

Referring now to the adjustable lamp support, the lamp 18, which is of the usual form with a single or double concentrated filament and a bayonet type or screw base, is supported in the usual way by a socket 1 1; and this socket is fastened to the inclined flange 15 of an arm A, having the general shape shown in Fig. 5. The socket 14c, which in the form shown is of the double contact type, is connected by flexible wires to a terminal block 16, from which wires (not shown) extend through the opening 10 in the casing C to the controlling contacts and devices for the signal.

To the arm A is riveted a stud 17 which fits in a hole in another arm B, having the form and shape shown in Fig. 1. The arm A, conveniently termed the socket arm, and the arm B, conveniently termed the supporting arm, are yieldingly held together fiatwise by a screw-headed bolt 18 passing through a hole 18 in the arm A (see Fig. 5) and a curved slot 19 in the arm B (see Fig. 1), together with a spring 20 interposed between the back ot the arm B and the jam nuts on the bolt 18. Thus while the arms A and B may turn relatively to each other about the axis of the stud 17, their relative movement is confined to such turning movement, notwithstanding the lost motion between the stud 17 and its hole unavoidable on account of mechanical clearance.

Swinging movement of the socket arm A relative to the supporting arm B is obtained with precision, and the two arms are held in the set position, by an adjusting screw 21, having a knurled head in the form shown, which passes loosely through a hole in an upturned ear 22 integral with the arm A, and is threaded through a parallel ear 23. integral with the arm B. A spring 24- is disposed between the two ears 22 and 23 to eliminate the relative movement of the arms A and B on accountof the lost motion due to the clearance in the threads. This spring 24 also produces frictional opposition to the turning of the screw 21 sufieient to prevent it turning under ordinary jar and vibration, and thereby providing a kind of self-locking adjustment. A jam nut 25 is preferably employed for positively locking the adjusting screw 21 in its different positions.

The supporting arm B has a sleeve 26 fastened to one end in any suitable manner, preferably by a press fit or riveting. A stud 27, riveted or otherwise secured to the bezel ring 8. passes through the sleeve 26 of the supporting arm B. Thus, the supporting arm B may turn, carrying with it the socket arm A, about the fixed axis of the stud 27, and also the arms A and B together as'a unit may be moved in and out along the axis of the lens, the sleeve 26 sliding on the stud 27. Interposed between the bezel ring 8 and the supporting arm B is a light compression spring 28 (see Fig. 7), which has its ends fitting orer studs riveted into said bezel ring and arm, as shown. This spring 28 not only acts to move the supporting arm B away from the bezel ring, but also exerts a tendency to tilt the arm and take up in one direction the lost motion between the sleeve 26 and the stud 27 unavoidable on account 0 mechanical clearance. The outer end portion of the stud 27 is threaded; and on this threaded portion is an adjusting nut 30, preferably split to clamp the threads. Another nut 81 on this stud 27, which may take the form of a thumb nut, serves to positively hold the split nut 30 in its different adjusted positions.

The swinging movement of the supporting arm B about the axis of the stud 27 is regulated by an eccentric 32, which is threaded on a stud riveted to the bezel ring 8, and which fits in a jaw 34: in the supporting arm B. The supporting arm B is slotted, as indicated at 35, so that the sides of the jaw .84 will press tightly against the eccentric 32. The upper end of the eccentric 32 is formed with parallel surfaces, indicated at to fit a wrench; and the eccentric is preferably formed with a saw cut lengthwise extending most of the way through, sufiicient to make the eccentric to press tightly against the threads. This frictional engagement of the eccentric 32 on the threads serves to retain it against ordinarily displacement in its different adjusted posi tions; but a lock nut 38 is preferably provided for positively holding the eccentric.

The point in space at which the lamp filament should be positioned to give a beam of the desired spread and intensity is defined to the best advantage by optical means giving sighting lines intersecting at the right point. In adjusting a lamp until its filament is at this point, it is desirable to provide for independent movement of the filament in three directions, so that the positioning of the lilament can be accomplished in separate steps by three adjustments, each of which can be made separately without materially changing any other adjustment. These three directions of movement of the lamp filament are preferably and conveniently made at right angles to each other, although it is evident that other angular relations could be used. Also, it facilitates manipulation to have the movement of the filament follow the sighting lines of the optical means.

The particular construction of adjustable lamp support shown and described provided for movement of the lamp socket and consequently the filament of the lamp, rectilinearly along and substantially parallel to the axis of the lens, by turning the nut 30 to shift the two arms A and B in and out on the stud 27. This permits shifting the lamp until its filament is in a plane approximately at right angles to the axis of the lens and passing through the focal point of the lens. By turning the eccentric 32, the lamp filament may be moved in this plane in an are about the stud 27 as a center. The radius of this are is relatively long as compared with. the small movement of the filament in the are ordinarily necessary to focus the lamp, and consequently the line of movement of the lamp filament, while strictly an arc, is practically a straight line. By turning the adjusting screw 21, the

socket arm A may be swung with respect to 'the supporting arm B, thereby moving the lam. filamentalon an are about the in 17 as a center. This radius is also long as compared with the length of the are over which the filament has to be moved,.so that the direction of movement of the filament is substantially a strai ht line. Thus, this adjustable lamp support provides for rectilinear movement along the axis of the lens and movement of the filament along approximately straight lines at right angles to each other in a plane substantially at right angles to the axis of the lens, the movements in these three directions being-made by independent adjustments. 7 To facilitate the manipulation of the adjustable lamp support, the parts are preferably proportioned and located, as can be seen from Fig. 1, so that the stud 27 and the pin 17 are approximately degrees apart with reference to the focal point of the lens; and the arcs over which the filament. move, as

thearms A and B are turned by the eccentric 22 and adjusting screw 21, are approximately along the two sighting lines of the finders F. In other Words, the pivotal axis on Which the arms A and B turn are located, as closely as practicable, to intersect the sighting lines ,1

of the finders F. Consequently, as the arms A and B are turned together about the stud 27, the filament moves along the sighting line for the upper finder F and transversely with respect to the sighting line for the side finder, with the result that the image of the filament changes during this adjustment in the side finder only. Similarly, swinging movement of the arm A about the pin 17 shifts the ima e of the filament in the u oer finder.

By virtue of this construction and arrange ment of parts, the focusing of a lamp may be more easily accomplished, because the adjustments can be made independently, or

simultaneously, as desired; and the shifting of the lamp filament transversely of the axis of the lens in each direction takes place with reference to one of the sighting lines sothat the displacement of the filament out of its correct position, so far as that particular adjustment is concerned, is directly visible.

In using the device, the adjustments can be made separately or simultaneously in any order found most expedient, depending on how much the filament is displaced from the,

focal point and the direction of this displacement. Ordinarily, it appears to be most expedient to turn the nut 80 first until the fi ament of a lamp is in the ri ht plane,

whereupon the arms A and B may be swungg separately or simultaneously until the image of the lamp filament comes at the right spot in both finders.

The adustable lamp support of this invention is characterized by an organization of movable parts which while requiring small space, provides for the adjustments in the different directions necessary and substantially along straight lines properly related to the sighting lines of the finders. Two of, I

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the adjustments are obtained by moving parts about pivotal axes; and provision for relative movement is not only cheaper than strict rectilinear or slidi= g motion, but also can be constructed by ordinary manufacturing methods so as to be free from relative displacement and lost motion. The adjustment in and out on the stud 27 is rectilinear; but on account of the length of the sleeve the lost motion due to mechanical clearance is slight, and moreover this lost motion is normally taken up in one direction by the spring 28. The adjustments in the different directions can be made with precision, and the various movable parts providing for these adjustments are frictionally held, so that the adjustments are in eflect self-locking. In addition, )ositive locking means is provided for each adjustment.

Fig. 8 shows a modified construction of the sliding and pivotal support for the arm B. In this construction, the sleeve 26 which, as in Fig. 7, is fixed to the arm B, passes through the arm B, is snugly slidable on stud 27, and projects from both sides, for the purpose of lengthening the sleeve. The spring 28 between the ring 8 and the arm B, surrounds the stud, and is made stiff enough to hold the arm B firmly against an adjusting nut 31, serving the place of the nuts 30 and 81 of Fig. 7, and thereby preventing tilting of said arm on account of the lost motion necessarily existing between the sleeve 26 and the stud 27.

Another feature of the invention relates to the back light. For various reasons,

familiar to those skilled in the art, it is sometimes desirable to provide an indication from the rear of the signal visible for a limited distance. In providing such a rear indication or back light, it is essential to avoid the possibility of light, such as sunlight or light from a locomotive headlight, shining through the signal and giving it the appearance of being lighted. In the particular construction illustrated, an inclined circular mirror 40, supported by a bracket d1 fastened to the inner bezel ring 8 (see Fig. 8) is arranged to reflect light from the lamp 13 through a bulls eye 42, plain or colored as desired, in the rear door 2 of the. signal casing. This bulls eye a2 is held in place by a bezel ring 43, with the usual gaskets, and is shielded by a small hood or screen i l. The mirror 40 and a bulls eye 42 are located with relation to the axis of the regular lenses 4 and 7 in such a way, as will be evident from the drawing, that light from an external source, transmitted through the bulls eye along its axis and reflected by the mirror, travels in a direction transverse to the axis of the main lens and strikes the inside of the casing where it is absorbed. The hood 44 extends far enough to prevent light striking the bulls eye 42 at such an angle as to pass directly through the main lens.

In this way, while a rear indication is'obtained without detracting from the etficiency of the main beam, there is no chance for a false phantom indication.

The particular construction and arrange ment of parts shown and described is obviously susceptible of modification and adaptation to suit varying conditions, without departing from the functions and principles of the invention; and I desire to have it understood that the embodiment of the invention shown is merely illustrative and can be modified without departing from the scope of the invention as defined in the claims.

IV hat I claim is 1. In a light signal having a light concentrating device with a focal point, an adjustable support for a lamp socket to permit positioning of the filament of the lamp at said focal point, comprising pivotally connected members movable together in an are about an 'axis parallel with the axis of said light concentrating device and rectilineally along said axis.

An adjustable support for the lamp sockets of light signals comprising, a fixed member, and two arms pivotally connected and supported by said member to turn together about an axis parallel with the axis of the pivotal connection of said arms, one of said arms having a. lamp socket fixed thereto.

3. An adjustable support for lamp sockets of light signals comprising, two arms pivo-tally connected for relative swinging movement, means supporting said arms to swing together about an axis parallel with said pivotal axis, and means for moving said arms as a unit in a direction parallelwith their pivotal axis.

a. In an adjustable lamp support of the type described, comprising a fixed member, a supporting arm adj ustably supported by said member for turning movement and rectilinear movement along the axis on which it turns, another arm pivoted to said support-- ing arm, a lamp socket carried by said other arm, and an adjusting means for said arms.

5. In a light signal having a lens, the combination with optical means indicating the focal point of said lens by two intersecting sighting lines transverse to the axis of the lens, a bezel ring retaining the lens in place, a lamp socket, a manually adjustable means including two members pivotally connected for relative swinging movement, andcommon rectilinear movement, supporting said socket from the bezel ring for independent movement of the lamp socket relatively thereto in three directions, one of said directions being parallel to the axis of said lens, and the other two being in arcs substantially parallel with said sighting lines.

6. In a light signal having a lens, the combination with optical means indicating the focal point of said lens by two intersecting sighting lines transverse to its axis, a lamp maintained in frictional locking relation.

In testimony whereof I hereby afiix my and a socket therefor, and manually adjustable means supporting said socket for independent movement of the filamet of the lamp in a line substantially parallel with the axis of the lens and along arcs of relatively long radii substantially parallel with said sighting lines.

7. In a light signal, a lens, a bezel ring retaining said lens in place, a stud fixed to said ring and extending substantially parallel with the axis of the lens, pivotally connected arms, one slidably and pivotally mounted on said stud, a lamp socket secured to the other arm, and manually adjustable means for gradually moving said arms relatively to each other and to said stud.

8. I11 a light signal, a lens, a bezel ring retaining said lens in place, a stud fixed to said ring substantially parallel with the axis of the lens, a supporting arm mounted on said stud for movement lengthwise thereof and also about its axis, a socket arm pivoted to the supporting arm on an axis substantially parallel with said stud and located substantially at right angles thereto with respect to the axis of the lens, a lamp socket fixed to the socket arm, and manually adjustable means for obtaining said movements of said arms gradually and independently.

9. In an adjustable lamp support of the character described, the combination with a lamp socket, of an arm pivoted on a fixed pivot and supporting said socket, a bifurcated portion at one end of the arm, and means comprising an eccentric received in and bearing snugly against the sides of the bifurcated portion of said arm for gradually moving said arm about said fixed pivot and for retaining it in its various moved positions.

10. In an adjustable lamp support of the type described, the combination with a lamp socket, of two relatively thin broad faced arms, pivotally connected with their faces in contact, said socket being fixed to one arm, means for adjusting said arms relatively to each other and comprising, cooperating screw threaded elements, and a spring for taking up the lost motion between said elements in one direction and means biasing said faces of said arms into contact at all times.

11. An adjustable lamp support of the type described comprising in combination with a fixed member and a lamp socket, two pivoted arms, said socket being fastened to one arm, means supporting the other arm on said fixed member for independent movements about an axis and along said axis, and separate adjusting means for regulating the relative pivotal movement of said arms, the pivotal movement of said other arm relative to said member, and the rectilinear movement of said other arm relative to said member, said adjusting means each including cooperating screw threaded element's resiliently signature.

JOSEPH FRED MERKEL. 

